Eggs should be placed in cold water in a stock pot or similar pot. They should be covered with water and allowed to come to a boil over a medium heat. High heat may cause them to vibrate and break the shells. They should be boiled at least eight minutes to insure the consistency is hard. Hard boiled eggs can be used in a variety of ways, but they also can be eaten in egg cups. Hard-boiled eggs in their shells can be stored in the refrigerator for many days.